Arm motor not moving at full strength, recalibration necessary?

[Kyledoo]

Hi all, we are competing in our second regional of the season this weekend(Buckeye) and we are having a little problem with our lifter arm.
When trying to control the movement of the arm up or down we are not achieving full power output. We can tell this because on the Dashboard feedback, the bar only goes about half as high as bars for our drivetrain. We have tried using both joysticks and buttons and everything gives the same results. We are programming in C++ and to set the power of the arm we simply declare the Victor as arm and then do arm->Set(stick2->GetY());
I was thinking there is some sort of calibration that is off, and don't know if this is a programming fix or the "hard reset" that I have read about when you recalibrate the victor using the reset button and some hard-coded values.
We applied battery voltage directly to the motor and it moves at the right speed.. Any help will be greatly appreciated!

[Vikesrock]

If the dashboard is not showing the PWM value reaching the maximum, then you do not need to recalibrate the victor itself, your issue is in code somewhere.

EDIT: Or some type of hardware issue with the joystick. Have you tried setting the motor to a constant value of 1 using a button? Check and make sure that you are not setting the motor speed in two different places in your code.

[Kyledoo]

Originally Posted by Vikesrock

If the dashboard is not showing the PWM value reaching the maximum, then you do not need to recalibrate the victor itself, your issue is in code somewhere.

EDIT: Or some type of hardware issue with the joystick. Have you tried setting the motor to a constant value of 1 using a button? Check and make sure that you are not setting the motor speed in two different places in your code.

I have tried hard coding the value and got the same results. I will double check the code, but I am pretty sure there is only one line that utilizes the arm motor.

[Greg McKaskle]

Check to see if the code matches the type of motor controller?

Greg McKaskle

[MamaSpoldi]

Originally Posted by Kyledoo

Hi all, we are competing in our second regional of the season this weekend(Buckeye) and we are having a little problem with our lifter arm.
When trying to control the movement of the arm up or down we are not achieving full power output. We can tell this because on the Dashboard feedback, the bar only goes about half as high as bars for our drivetrain. We have tried using both joysticks and buttons and everything gives the same results. We are programming in C++ and to set the power of the arm we simply declare the Victor as arm and then do arm->Set(stick2->GetY());
I was thinking there is some sort of calibration that is off, and don't know if this is a programming fix or the "hard reset" that I have read about when you recalibrate the victor using the reset button and some hard-coded values.
We applied battery voltage directly to the motor and it moves at the right speed.. Any help will be greatly appreciated!

We noticed the exact same thing when using the Victor class. Try using the Jaguar class instead... that worked for us. I know it sounds wrong and I understand that the hardware you are using is actually a Victor motor controller, but when we accidentally used a Jaguar object to interface to a Victor it worked great when we "fixed" it to be a Victor it had the same problem you describe. I haven't taken the time to look at the implementation of the 2 classes (ie. Jaguar and Victor), but suffice it to say that it works "correctly" with the Jaguar object controlling a Victor motor controller.

[Greg McKaskle]

IIRC, the major difference for PWM is that the Jag update period is 5ms and the Victor is 10. I suppose it is better to treat a Jag like a Victor than a Victor like a Jag, but better still is to match the timing to the device.

Greg McKaskle

[Joe Ross]

I think you're seeing a display issue only. Check the LED on the victor. If it goes solid green or red, that means it's getting full power.

The Jaguar uses a longer PWM pulse then the victor does. Thus, the PWM class (which Jaguar and Victor extend), has to work with both. It uses 251 PWM for the longest pulse a jaguar can take. 210 is the longest pulse a Victor can take. You can see these values in the initVictor and initJaguar functions. When the dashboard sends values, it uses the raw PWM values, so the largest value you'd ever see is 210, which would look approximately half speed on the dashboard display. The LED on the victor really says what speed it's going.

Changing from the victor class to the jaguar class fixed the display issue, but it can really confuse the victor controller, since it is now being updated faster then it can take, and with longer pulses then it was designed for.

If you want to fix the dashboard display, you can scale the values for the victors up to a 0-254 range. That would be the best solution.